Only once.
When you have paid for the game you get all it's features and updates for free.
Once.
Nothing will happen if you keep installing and uninstalling Minecraft. Minecraft does not track how many times you have installed it nor does track how many computers you have it installed on. The only drawback is if you uninstall Minecraft by deleting the .minecraft folder you will lose all of your saved worlds on that computer.
Notch is no longer in charge of Minecraft :(
3 times,
Many mod developers do not charge for mods however some fee's may be charged if a bukkit plugin needs to be specially coded however it is choice of the coder how much they want to charge you.
No, there is no additional fee.
Minecraft does not charge you to run a server for the game. You will, however, have to posses a computer to be the server. Otherwise you will have to rent a server to run for you, which costs money.
Around 600 times
It depends on whatever Herobrine mod you've installed.
No, It shouldn't have "Charged the internet" the only payment you have to go through is when you purchase a premium Minecraft account.
While the user licence of minecraft does allow people to charge for modifications (mods), most mods are published for free.
While it is possible and legal to charge for a mod, most mods for Minecraft are provided free of charge. However, most modders will accept donations to help support their work.